Vagal nerve stimulation dynamically alters anxiety-like behavior in rats

Abstract

Background: Electrical vagal nerve stimulation (VNS), at currents designed to target sensory, interoceptive neurons, decreases anxiety-like behavior. Objective/Hypothesis: We hypothesized that different VNS current intensities would differentially alter anxiety-like behavior through the activation of distinct brainstem circuits. Methods: Electrodes were implanted to stimulate the left vagus nerve and to record diaphragm muscle and electrocardiogram activity. The VNS current required to elicit the A-fiber-mediated Hering-Breuer Reflex (HBR) was determined for each animal. Based on this threshold, animals received either sham stimulation or VNS at 1.5 (mid-intensity VNS) or 3 (higher-intensity..